MrgprX2-IN-2 (Compound example 12) is a selective antagonist of the Mas-related G protein-coupled receptor X2 (MRGPRX2). It works by inhibiting MRGPRX2-mediated mast cell degranulation and the release of inflammatory mediators, thus blocking non-IgE-dependent immune responses. MrgprX2-IN-2 shows potential for research in the areas of pseudo-allergic reactions, chronic pruritus, and inflammatory diseases.